Location and History
This district is in east-central Madera County at the site of the old town of Grub Gulch, seven miles north of Coarsegold and 35 miles northeast of Madera. The site is at the northwest end of a 20-mile-long belt that extends from here southeast through the Coarsegold and Fine Gold districts. This district has been the most productive portion of this belt. It includes part of the area that also was known as the Potter Ridge district. The camp was established shortly after the discovery of Coarsegold in 1849. There was much activity from the 1880s through the early 1900s but very little mining has been done since. A few small suction dredges were active in the 1940s and 1950s downstream in the Chowchilla River.
Geology and Ore Deposits. The district is underlain by a northwest-trending belt of mica schist and quartzite with granodiorite to the west. A series of gold-quartz veins are variously oriented. The veins range from one to 10 feet in thickness. The ore contains free gold and varying amounts of sulfides. The milling-grade ore was reported to have yielded up to one ounce of gold per ton. The greatest depth of development is 800 feet.
Mines
Bullion, Butterfly, Conary, Crystal Spring, Enterprise $100,000, Gambetta $500,000, Hoboken, Josephine $360,000, Lucky Bill, Savannah, Starlight, Woodland.
Bibliography
Irelan, William, Jr., 1890, Potter Ridge mining district: California Min. Bur. Rept. 10, pp. 197-204.
Mclaughlin, R.P., and Bradley, W. W., 1916, Madera County, gold: California Min. Bur. Rept. 14, pp. 539-553.
